Windows Server 2016[1] is an upcoming server operating system
developed by Microsoft as part of the Windows NT family of
operating systems, developed concurrently with Windows 10. The
first early preview version (Technical Preview) became available on
1 October 2014 together with the first technical preview of System
Center,[2] and is currently in public beta testing. The final
release date for the server is expected to be in Q3 2016, that is,
not released simultaneously with the client operating system
Windows 10 as was the case with the last three operating system
releases.

Storage Services: central Storage QoS Policies; Storage Replicas
(storage-agnostic, block-level, volume-based, synchronous and
asynchronous replication using SMB3 between servers for disaster
recovery).Storage Replica replicates blocks instead of files; files
can be in use. It's not multi-master, not one-to-many and not
transitive. It periodically replicates snapshots, and the
replication direction can be changed.

Rolling Hyper-V cluster update: unlike upgrading clusters from
Windows 2008 R2 to 2012 level, Windows Server Technical Preview
cluster nodes can be added to a Hyper-V Cluster with nodes running
Windows Server 2012 R2. The cluster continues to function at a
Windows Server 2012 R2 feature level until all of the nodes in the
cluster have been upgraded and the cluster functional level has
been upgraded.

Storage quality of service (QoS) to centrally monitor end-to-end
storage performance and create policies using Hyper-V and Scale-Out
File Servers

Microsoft has been reorganized by Satya Nadella, putting the Server
and System Center teams together. Previously, the Server team was
more closely aligned with the Windows client team. The Azure team
is also working closely with the Server team.

Releases

Preview releases

Main article: Windows Insider

A public beta version of Windows Server 2016 (then still called
vNext) branded as "Windows Server Technical Preview" was released
on October 1, 2014; the technical preview builds are aimed towards
enterprise users. The first Technical Preview was first set to
expire on 15 April 2015 but Microsoft later released a tool to extend the expiry date, to last
until the second tech preview of the OS in May 2015.The second beta
version, "Technical Preview 2", was released on May 4, 2015. Third
preview version, "Technical Preview 3" was released on August 19,
2015. "Technical Preview 4" was released on November 19, 2015.

Public release

Windows Server 2016 is expected to be released to manufacturing
sometime in 2016. Unlike its predecessor, Windows Server 2016 is
licensed by the number of CPU cores rather than number of CPU
sockets—a change that has similarly been adopted by BizTalk Server
2013 and SQL Server 2014.

Other: Conditional access control in AD FS; application
authentication support for OpenID Connect and OAuth; full OpenGL
support with RDS for VDI; Server-side support for HTTP/2, including
header compression, connection multiplexing and server push[28]

Nano Server supports the DNS Server and IIS server roles, as well
as MPIO, VMM, SCOM, DSC push mode, DCB, Windows Server Installer,
and the WMI provider for Windows Update. Its Recovery Console
supports editing and repairing the network configuration. A Windows
PowerShell module is now available to simplify building Nano Server
images.[32]